3.3.1 The scrubber should be of a design related
to the type of tanker, cargoes and combustion control equipment of
the inert gas supply source and be capable of dealing with the quantity
of inert gas required by regulation 62 at
the designed pressure differential of the system.
3.3.2 The performance of the scrubber at full
gas flow should be such as to remove at least 90% of sulphur dioxide
and to remove solids effectively. In product carriers more stringent
requirements may be needed for product quality.
3.3.3 The internal parts of the scrubber should
be constructed in corrosion-resistant materials in respect of the
corrosive effect of the gas. Alternatively, the internal parts may
be lined with rubber, glass fibre epoxy resin or other equivalent
material, in which case the flue gases may require to be cooled before
they are introduced into the lined sections of the scrubber.
3.3.4 Adequate openings and sight glasses should
be provided in the shell for inspection, cleaning and observational
purposes. The sight glasses should be reinforced to withstand impact
and be of a heat resisting type. This may be achieved by the use of
double glazing.
3.3.5 The design should be such that under normal
conditions of trim and list the scrubber efficiency will not fall
by more than 3%, nor will the temperature rise at the gas outlet exceed
the designed gas outlet temperature by more than 3°C.
3.3.6 The location of the scrubber above the load
waterline should be such that the drainage of the effluent is not
impaired when the ship is in the fully loaded condition.